[0001] This invention relates to a surgical drainage device which is designed to drain fluids
from a body cavity such as the pleural cavity and to maintain proper pressures within
the body cavity.
[0002] It is essential for normal breathing that the space within the pleural cavity surrounding
the lungs be free of liquid and be subject to a negative pressure so as to draw the
lungs outwardly to fill this pleural cavity in order to permit proper breathing. Any
invasion of the pleural cavity such as by lung surgery or by foreign objects which
pierce the ribcage or, for example, where the patient has pleurisy, generates fluids
in the pleural cavity which tend to obstruct normal breathing. It is necessary to
provide a device which can remove these fluids from the pleural cavity and, at the
same time, ensure that negative pressure is maintained within the pleural cavity.
[0003] Examples of one of the basic types of devices used for the above purposes are disclosed
in U.S. Patents 4,015,603; 4,261,362; 4,312,351 and 4,324,244. In this type of device
an underwater seal chamber is formed at the top of the device by a wall or partition
extending across a portion of the device. An underwater seal is created in the underwater
seal chamber beneath the inlet to the device by liquids drained from the patient's
body. The underwater seal serves as a diagnostic aid in the detection of leaks during
inspiration in the pleural cavity or the drainage system. Also, it provides an additional
barrier against the flow of atmospheric air from the device into the pleural cavity
of the patient. Since the liquid seal does not have to be established by prefilling
with water, this type of device is ideally-suited for use in emergency situations.
Another important feature in this type of device is a one-way outflow valve located
adjacent the outlet (which may be connected to a vacuum source or open to the atmosphere).
This valve permits the escape of gases from within the device when the pressure therein
is above that at the outlet but prevents the passage of atmospheric air into the device.
As a result, the possibility of passage of atmospheric air or liquid from the liquid
seal into the pleural cavity of the patient, of concern particularly during periods
of high negative pressure in the pleural cavity, is greatly reduced.
[0004] However, a significant problem may sometimes arise with this type of device. Gases
flowing from the pleural cavity of the patient through the liquid seal to the outlet
may entrain relatively small amounts of the liquid in the seal and conduct it towards
the one-way valve adjacent the outlet. This phenomenon tends to occur particularly
when the liquid drained from the patient has a pronounced tendency to foam (e.g. blood
and other proteinaceous liquids). Liquid contact with the one-way valve must be avoided
since it can lead to impairment of the mechanical functioning of the valve.
[0005] The present invention comprises a novel drainage device comprising a housing, an
inlet in the upper wall of said housing for liquids-and gases from the body of a patient,
a partition extending across a portion of the housing to form an underwater seal chamber
above the partition and beneath the inlet and a collection chamber below the level
of the partition for receiving said liquids and gases, with the partition being spaced
from the housing to provide an opening to permit the flow of gases and liquids from
the underwater seal chamber to the collection chamber, a tubular extension connected
to the inlet and extending downwardly into the underwater seal chamber whereby liquids
from the body of the patient are collected in the underwater seal chamber and provide
a liquid seal with the lower end of the tubular extension, means for providing an
outlet for gases from the housing, said outlet means including an outlet in the housing
and a one-way valve for allowing the passage of gases in one direction only from the
collecton chamber to the outlet, a trap chamber located between the inflow side of
the one-way valve and the collection chamber for collecting liquids which are inadvertently
conducted toward said valve, and a passageway connecting the collection chamber with
the trap chamber. A critical feature of the present invention is that the underwater
seal chamber is closed off from the trap chamber and the gas flow is diverted through
the collection chamber. This diversion greatly reduces the possibility of conducting
entrained liquid into the trap chamber and toward the one-way valve.
[0006] The invention will be described in detail with reference to a preferred embodiment
thereof. Reference to this embodiment does not limit the scope of the invention, which
is limited only by the scope of the claims.
[0007] In the drawings:
.FIG. 1 is a front elevation view of an underwater chest drainage device of the invention;
FIG. 2 is a left end elevation view of the drainage device of FIG. I;
FIG. 3 is a section view taken along line 3-3 of FIG. 1; and
FIG. 4 is an enlarged perspective view of certain internal features of the drainage
device of FIG. 1 adjacent the outlet of the device.
[0008] A drainage device 1 of the present invention is shown in FIGS. 1 to 4. Device 1 comprises
a generally box-shaped housing 3 having a front wall 5, a rear wall 7, end walls 9
and 11, a top wall 13 and a bottom wall 15. Housing 3, which is preferably made of
a rigid transparent plastic material, is formed by bonding front wall 5 to a unitary
piece comprising the other five walls of the housing. As shown in FIGS. 1 and 2, front
wall 5 is provided with marginal portions extending beyond the points at which it
is bonded to walls 9, 11, 13 and 15, for example by solvent welding.
[0009] Drainage device 1 is provided with an inlet 17 in top wall 13 for attachment to a
thoracotomy tube which extends into the pleural cavity of the patient and an outlet
19 also in top wall 13 for attachment to a source of suction. (In certain modes of
operation of the device, outlet 19 is left open to the atmosphere.)
[0010] Housing 3 is also provided with two openings providing access to the interior of
the housing. The first opening, which is. in wall 9, provides access for the installation
of one-way valve 89 during the manufacture of device 1. After said installation, this
opening is closed by bonding cover 23 to wall 9. The second opening is closed by cover
21 in sealing engagement over a rubber grommet with wall 7. Cover 21 is provided with
a central rubber portion 22. This opening provides access, if desired, to prefill
the underwater seal with water.
[0011] As is shown in FIG. 1, drainage device 1 includes an internal partition 25 extending
across (from left- to-right in FIG. 1) a portion of housing 3. Partition 25, which
extends the full distance between front wall 5 and rear wall 7, defines and forms
an underwater seal chamber 27 between partition 25 and top wall 13 and beneath inlet
17. Additionally, partition 25 defines and forms beneath its level a collection chamber
29 for receiving liquids and gases from the patient's body. In the preferred embodiment
of the invention shown in FIGS. 1 to 4, the main body of collection chamber 29 is
divided into three collection wells 31, 33 and 35 by vertical walls 37 and 39.
[0012] As is best shown in FIG. 1, drainage device 1 includes a tubular extension 41 connected
to inlet 17 and extending downwardly therefrom into underwater seal chamber 27. As
will be described in more detail below, liquids from the body of the patient are collected
in underwater seal chamber 27 during the operation of device 1 and thereby provide
a liquid seal with the lower end of tubular extension 41. As shown in FIGS. 1 and
4, partition 25 is spaced from end wall 11 to provide an opening 43 to permit the
flow of gases and liquids from underwater seal chamber 27 to collection chamber 29.
Preferably, as shown in the figures, partition 25 includes a substantially flat portion
45 gradually sloped (at about 2° to about 3°) downwardly towards a cup-like portion
47 located below the lower end of tubular extension 41. Cup portion 47 is sized so
as to satisfy two somewhat conflicting criteria. The purpose of cup portion 47 is
to retain liquid drained from the pleural cavity so that after a predetermined amount
of liquid has been drained and the bottom of inlet tube 41 is covered, a seal is automatically
formed. Thus, one criterion is that cup portion 47 be small enough so that only a
relatively small amount of liquid needs to be drained from the pleural cavity of the
patient before a seal is formed. On the other hand, it is an important feature of
the present invention that the seal, once formed, not be destroyed by the inadvertent
tilting of drainage device 1. Hence, cup portion 47 should have a sufficiently large
capacity that should some liquid be lost therefrom, the seal will not be broken. The
sloping of partition portion 45 permits the liquid accumulating in underwater seal
chamber 27 to flow in the direction of cup portion 47. Device 1 is also provided adjacent
opening 43 with a gate 93 extending above the end of cup-like portion 47 and a drip
ledge 95 extending below the end of said portion.
[0013] Walls 49, 51, 53, 55 and 57 separate an upper corner of the interior of housing 3
from the remainder of said interior. Walls 55 and 57 also form the end of underwater
seal chamber 27 opposite from opening 43. Additionally, internal walls 61, 63, 65
and 67, each of which extends between walls 5 and 59, further divide said inner corner
into a trap chamber 75, a flow chamber 77, a connecting chamber 79 and an outflow
chamber 81. These chambers are connected by passageway 85 (between chambers 75 and
77), passageway 87 (between chambers 77 and 79) and a one-way outflow valve 89 positioned
on wall 67 (between chambers 79 and 81).
[0014] As can be seen in FIGS. 1 and 4, wall 61 is a vertical extension of wall 51. Collection
chamber 29 and trap chamber 75 are connected by means of passageway 97 in wall 55.
However, no direct fluid connection is provided between underwater seal chamber 27
and trap chamber 75. The space generally defined beyond walls 49, 55, 57 and 59 which
is designated in FIGS. 2 and 3 as 83 is exterior to device 1. A one-way outflow valve
of suitable construction for use in the device of the present invention is disclosed
in U.S. Patents 4,312,351 and 4,324,244, which patents are incorporated herein by
reference. When the pressure in underwater seal chamber 27, collection chamber 29,
trap chamber 75, flow chamber 77 and connection chamber 79 exceeds the pressure in
outflow chamber 81, one-way valve 89 is forced open so as to permit the passage of
gases into outflow chamber 81 and to outlet 19. However, when the pressure is higher
within outflow chamber 81 than within the remainder of drainage device 1, one-way
valve 89 remains closed preventing gas flow in the opposite direction. Preferably,
the device 1 includes a positive pressure relief valve 91, e.g. of the type described
in the above-mentioned U.S. Patents 4,312,351 and 4,324,244.
[0015] The purpose of valve 91, which is shown in the figures of the present application
as housed in fluid communication with outflow chamber 81 between walls 9, 13, 59,
69, 71 and 73, is to provide a means for the release of high positive pressure to
the atmosphere in the event that very high pressures are inadvertently reached within
the interior of the drainage device. The positive pressure relief valve remains closed
during the normal operation of the drainage device. If desired, an air flow meter
(not shown in the figures) for measuring the rate of flow of gases through the outlet
may be located within flow chamber 77. This meter may be, for example, of the rising
ball type.
[0016] If any liquid from underwater seal chamber 27 should inadvertently be carried by
the gas flow through passageway 97, this liquid will collect in trap chamber '75 and
thus be prevented from impairing the mechanical functioning of one-way valve 89 or,
if present, an air flow meter in flow chamber 77. If sufficient liquid is collected
in trap chamber 75, it will overflow through passageway 97 back into collection chamber
29.
[0017] When drainage device 1 is used, it is normally used with a suction from a regulated
suction source attached to outlet 19. A hose from the regulated suction source is
attached to outlet 19 and the desired degree of negativity is maintained within device
1 and the pleural cavity. However, in some situations device 1 can also be used without
an external suction source. In either case, drainage device 1 may be used without
prefilling the liquid seal. A thoracotomy tube (not shown in the figures) is connected
between the pleural cavity of the patient and inlet 17. One-way outflow valve 89 prevents
the passage of atmospheric air to the patient with the resulting danger of pneumothorax
or contamination. The liquid secretions from the pleural cavity of the patient are
initially collected in cup-like portion 47 of partition 25 and quickly form a liquid
seal at the lower end of tubular extension 41. As additional liquid is collected,
the liquid in the underwater seal chamber 27 overflows gate 93 and is then collected
in collection chamber 29.
[0018] As drainage device 1 operates to collect fluids from the pleural cavity of the patient,
liquids from the pleural cavity are collected.in collection chamber 29 (in addition
to the limited amount held in underwater seal chamber 27) while gases which are passed
from the pleural cavity into drainage device 1 are subsequently conducted out of the
device. These gases follow a flow path through inlet 17, tubular extension 41, underwater
seal chamber 27, opening 43, collection chamber 29, passageway 97, trap chamber 75,
flow chamber 77, connection chamber 79, one-way outflow valve 89, outflow chamber
81 and outlet 19 (note arrows in FIG. 1). Since underwater seal chamber 27 is closed
off from trap chamber 75 by walls 55 and 57 and these two chambers are not in direct
fluid communication with each other, flow of said gases from the underwater seal chamber
27 directly to the trap chamber 75 does not occur. Because of the prevention of direct
gas flow between the underwater seal chamber and the trap chamber and the consequent
diversion of the gas flow to the more indirect route through the collection chamber,
the likelihood that any significant quantity of entrained liquid might be carried
by the gas flow from the underwater seal chamber to the trap chamber is quite low,
even when the liquid in the liquid seal has a pronounced foaming tendency. This likelihood
is even further reduced because of the configuration of drip ledge 95, which comprises
a substantially vertical portion 99 and a portion 101 extending under opening 43 at
an oblique angle with respect to portion 99. Because of this drip ledge configuration
liquid overflowing gate 93 is diverted in a direction toward wall 11, thereby insuring
that collection wells 31, 33 and 35 will be filled with liquid in that order. This
has two desirable consequences. First, during at least the early stages of a drainage
procedure (until well 31 is filled) any liquid foam overflowing gate 93 will be diverted
to and collected in well 31. This foam will be physically removed from the gas flow
path (note arrows in FIG. 1) and will thus be given time to collapse before it can
be swept toward passageway 97 as a gas-entrained liquid. Second, because of the sequential
filling of wells 31, 33 and 35, the operating personnel can readily determine by brief
observation the precise total quantity of liquid drained from the patient at any particular
time during the operation of the device.
[0019] Another advantageous feature of the present invention is its stability against disruption
of function by accidental tilting. Should housing 3 be inadvertently tilted towards
wall 11, gate 93 serves to maintain liquid in underwater seal chamber 27. Since chamber
27 is closed off from trap chamber 75, liquids cannot escape from chamber 27 in the
event of an inadvertent tilting of housing 3 towards wall 9. Thus, gate 93, wall 55,
wall 57 and sloping portion 45 of partition 25 act together to maintain a sufficient
reservoir of liquid in underwater seal chamber 27 to keep the liquid seal intact.
[0020] While drainage device 1 can rest on a table, floor, etc. it is preferred to provide
one or more hanger attachments, such as attachments 103 and 105 to allow the device
to be hooked onto a bedside or otherwise stabilized. Other suitable hanger arrangements
that may be used to stabilize drainage devices of the present invention are disclosed
in the above-mentioned U.S. Patents 4,312,351 and 4,324,244.
1. A drainage device comprising a housing (3); an inlet (17) in the upper wall (13)
of said housing (3) for liquids and gases from the body of a patient; a partition
(25) extending across a portion of said housing (3) to form an underwater seal chamber
(27) above said partition (25) and beneath said inlet (17) and a collection chamber
(29) below the level of said partition (25) for receiving said liquids and gases,
with said partition (25) being spaced from said housing (3) to provide an opening
(43) to permit the flow of gases and liquids from said underwater seal chamber (27)
to said collection chamber (29); a tubular extension (41) connected to said inlet
(17) and extending downwardly into said underwater seal chamber (27) whereby liquids
from the body of the patient are collected in the underwater seal chamber (27) and
provide a liquid seal with the lower end of said tubular extension (41); means for
providing an outlet for gases from said housing, said outlet means including an outlet
(19) in said housing (3) and a one-way valve (89) for allowing the passage of gases
in one direction only from the collection chamber (29) to said outlet (19); a trap
chamber (75) located between the inflow side of said one-way valve (89) and said collection
chamber (29) for collecting liquids which are inadvertently conducted toward said
valve (89); and a passageway (97) providing an inlet for the flow of gases to said
trap chamber (75), characterized in that said passageway (97) connects the collection
chamber (27) with said trap chamber (75), said underwater seal chamber (27) and said
trap chamber (75) are not in direct fluid communication with one another, and a flow
path of gases from the body of the patient is established through said inlet (17),
said tubular extension (41), said underwater .seal chamber (27), said opening (43),
said collection chamber (29), said passageway (97), said trap chamber (75), said one-way
valve (89) and said outlet (19).
2. A drainage device of claim 1 further characterized in that said outlet means comprises
additionally a positive pressure relief valve (91) located downstream of said one-way
valve (89).
3. A drainage device of claim 1 further characterized in that said device comprises
additionally an air flow meter located in said housing (3) between said trap chamber
(75) and said one-way valve (89) for measuring the rate of flow of gases through said
outlet (19).
4. A drainage device of claim 1 further characterized in that said partition (25)
includes a substantially flat portion (45) gradually sloped downwardly towards a cup-like
portion (47) located below the lower end of said tubular extension (41), with said
opening (43) being located between the end of said cup-like portion (47) and said
housing (3).
5. A drainage device of claim 4 further characterized in that said device comprises
additionally, adjacent said opening (43), a gate (93) extending above the end of said
cup-like portion (47) and a drip ledge (95) extending below the end of said cup-like
portion (47), with said drip ledge (95) comprising a substantially vertical portion
(99) extending downwardly from said end and a portion (101) extending under said opening
(43) at an oblique angle with respect to said substantially vertical portion (99).